Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754024Ab0LMTeU (ORCPT ); Mon, 13 Dec 2010 14:34:20 -0500 Received: from mail-pz0-f46.google.com ([209.85.210.46]:49398 "EHLO mail-pz0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753887Ab0LMTeS (ORCPT ); Mon, 13 Dec 2010 14:34:18 -0500 Date: Mon, 13 Dec 2010 12:34:08 -0700 From: Eric B Munson To: Mel Gorman Cc: Andrew Morton , Simon Kirby , KOSAKI Motohiro , Shaohua Li , Dave Hansen , Johannes Weiner , linux-mm , linux-kernel Subject: Re: [PATCH 1/6] mm: kswapd: Stop high-order balancing when any suitable zone is balanced Message-ID: <20101213193408.GC3401@mgebm.net> References: <1291995985-5913-1-git-send-email-mel@csn.ul.ie> <1291995985-5913-2-git-send-email-mel@csn.ul.ie> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="/e2eDi0V/xtL+Mc8" Content-Disposition: inline In-Reply-To: <1291995985-5913-2-git-send-email-mel@csn.ul.ie> User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2156 Lines: 55 --/e2eDi0V/xtL+Mc8 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Fri, 10 Dec 2010, Mel Gorman wrote: > When the allocator enters its slow path, kswapd is woken up to balance the > node. It continues working until all zones within the node are balanced. = For > order-0 allocations, this makes perfect sense but for higher orders it can > have unintended side-effects. If the zone sizes are imbalanced, kswapd may > reclaim heavily within a smaller zone discarding an excessive number of > pages. The user-visible behaviour is that kswapd is awake and reclaiming > even though plenty of pages are free from a suitable zone. >=20 > This patch alters the "balance" logic for high-order reclaim allowing ksw= apd > to stop if any suitable zone becomes balanced to reduce the number of pag= es > it reclaims from other zones. kswapd still tries to ensure that order-0 > watermarks for all zones are met before sleeping. >=20 > Signed-off-by: Mel Gorman > Reviewed-by: Minchan Kim > Reviewed-by: KAMEZAWA Hiroyuki Started reviewing before I saw this series. Reviewed-by: Eric B Munson --/e2eDi0V/xtL+Mc8 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.10 (GNU/Linux) iQEcBAEBAgAGBQJNBnUwAAoJEH65iIruGRnNYksH/0Q6qqkuy5cHyFc5tXrSAcuZ mBmDyjuxATuedCeuMtBoNhjTTAomuPp6RqJzeqFPptWSzaDMMcXlkh8ToNJPuniH B7lIYHPe1qLP5YCRQ1OAl+U8u+EBFg6h5GgxKGSzJXgAE/sNNkZpysnL6spcOHXk 0CXS4dGiGNZVef4zBIkB+/cQ4pgj46okdNGGDbAfkAXah9Le8+3oL5zNSLoEhK6J s6PxkDoycJcH61fKQC6P9cZZ8EPZk+rJFrKEQ4nDjdBwfZCLI3EQ2t9Njr1bmJtt e9n6H3DCj+vOuz1QNyrjlwPL9N6D7yhyHKdZWCrEsCT0PIqLaysQTZVmh+PPPwI= =W6G+ -----END PGP SIGNATURE----- --/e2eDi0V/xtL+Mc8-- -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/